Breech block removing tool



2 Sheets-Sheet 1 W. KUPER April 10, 1956 BREECH BLOCK REMOVING TOOL Filed June 14, 1954 m P m W. a W N .sk D Q 1% M Y IM-- I M W A w ll z. i O Q =fiw a 5% N v\ Q April 195.6 B. w. KUPER BREECH BLOCK REMOVING TOOL 2 Sheets-Sheet 2 Filed June 14, 1954 INVENTOR BERNARD W. -KUF'E/i BY jam QT am United States Patent BREECH BLOCK REMOVING TOOL Bernard W. Kuper, United States Navy Application June 14, 1954, Serial No. 436,745

2 Claims. (Cl. 29-1.;1) (Granted under Title 35, U. S. Code (1952), sec. 266) The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

The invention relates to improvements in disassembling apparatus and more specifically to a tool for use in removing the breech block from an automatic gun of the type shown in U. S. Patent 1,556,225.

The major difference between this type gun and others is that, upon firing most guns, the force of the explosion is taken by a locked breech block and by recoil mechanism, whereas in this gun, the explosion is absorbed in checking and reversing the forward movement of a relatively heavy bolt, or breech block, that is not locked. A barrel spring supplies the only force tending to keep the breech block closed. Among the casualties suffered by this type gun are broken face piece, broken striker, and broken hammer, all located on the breech block.

While the recocking bar on certain types of mounts could be utilized for removal of the breech block, it is seldom used for that purpose because often it does not draw the breech bars back far enough to permit removal of the cotter, it cannot be used while the gun is removed from the mount, the gun cannot be fired while it is in place, and there is a possibility of the mount securing latch being knocked down during confusion.

An important object of the present invention is to provide a tool for use in removing the'breech block from the gun mechanism in the least amount of time and with minimum effort. 7

Another object of the invention is the provision of a tool of the character described which can be applied to mounted or unmounted guns, and to one of the guns in a twin mount so that, during combat, a disabled gun may be repaired while its companion gun is being fired.

A further object is to provide a tool of the character described which will facilitate proper compression of the barrel spring so that the breech block cotter may be removed.

A still further object is the provision of a tool of the character described which can be applied to the gun and operated in a minimum amount of time.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

Fig. 1 is a fragmentary view in side elevation of the gun with its breech bars forward and with the breech block removing tool attached;

Fig. 2 is a fragmentary horizontal sectional view taken substantially on the line 2-2 of Fig. 1;

Fig. 3 is a fragmentary view in side elevation similar to Fig. l but with the breech bars drawn aft and the breech block removing tool handle maintained in its rear position by the magazine catch lever of the gun; and

Fig. 4 is a perspective view of the tool.

2,741,! 1 Patented Apr. 10, 1956 17 and the breech block 13, to urge the breech block into its forward, closed or firing position. When the breech block is forward and the parts are positioned as shown in Figs. 1 and 2, the barrel spring load being transmitted from the breech bars to the breech block through the transverse cotter 18 produces a shearing load and a binding which makes difiicult the removal of the cotter.

Formed on the breech casing is a magazine anchoring fulcrum 19 normally receiving the forward end of a magazine (not shown), which is releasably engageable at its after end by a magazine catch lever 20, mounted on the breech casing.

The tool 21 comprises a hinged clamp 22, adapted to embrace the right and left breech bars 16, 17 and to be releasably fastened thereto in engagement with the breech bar lugs 23, as by a bolt 24 and wing nut 25.

Pivotally connected to the upper end of the clamp, at a transversely apertured lug 26 aflixed thereon, is the laterally bent end portion 27 of a link 28. The end portion 27 may be maintained in pivoted relation to the lug as by a taper pin 29. The other end portion 30 of the link 28 is pivotally connected as by a stud 31 to a hand lever 32 provided at one end with a transverse pivot pin 33 and at its opposite end with a laterally bent handle portion 34. The pivot pin 33 is arranged to seat against the forward magazine anchoring abutment 19, as shown in Fig. 1.

By pulling the lever 32 aft with a backward and downward movement, the breech bars are drawn back to compress the barrel springs 14 and relieve tension on the breech bar cotter 18. The lever 32 is locked in the aft position by the magazine securing lug 35 under the control of the magazine catch lever 20. From an inspection of Fig. 3, it will be seen that the link 28 is provided with an intermediate obtuse angular bend 36 which allows clearance between the link and breech casing when the lever is in its rearwardly and downwardly swung position. After the tension on the breech bar cotter is relieved, removal of the breech bar securing pins, cotter, and back plate is undertaken preparatory to rearwardly sliding out the breech bolt and block for repairs.

Obviously many modifications and variationsof the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is:

l. A tool for use in removing the breech block from an automatic gun of the type including a barrel provided with a breech casing, said casing having a magazine anchoring fulcrum and a magazine catch lever thereon, a breech block longitudinally reciprocable in the casing, a barrel spring encircling the barrel forwardly of the breech casing, longitudinally reciprocable breech bars loaded in tension by said barrel spring, and a transversely removable cotter pin connecting said breech bars and breech block transmitting said tension load to the breech block whereby the breech block is urged toward closed position and the rearward momentum of thebreech block and breech bars is absorbed by the barrel spring, said tool comprising a clamp releasably engageable with said Breech bars, a lever includinga pivot pin s e'atable against the magazine anchoring fulcrum, and .a link opcratively connecting the lever and clamp, said lever being swingable to a retracted position wherein said breech bars are drawn rearward-1y against the fierce of is-aid barrelspring, thus relieving the tension load normally transmitted from the breech bars to the breech block and facilitating extraction of said cotter .pin preliminary to removal of "said breech block.

2. 'A tool for use in removing the breech block from an automatic gun of the type including a barrel pr0- vided with abreech casing, said casing having a magazine anchoring fulcrum forwardly thereon and a magazine catch device "r'earwardly thereon, a breech bloclc longitudinally reciprocable in the -casing,"a bar'rel spring encircling the barrel forwardly of the breech casing, longitudinally reciprocablc'bree'ch bars loaded in tension by said barrel spring, and a transversely removable cotter pin connecting said breech barsand breech block transmitting said tension load to the breech block whereby the breech block is urgedtoward closed position'and the clamp releasably attachable to said breech bars, a lever having a pivot portion arranged to perch against said magazine anchoring fulcrum, and a link operatively connecting the lever and clamp, said lever being swingable to a retracted position wherein said breech bars are drawn rearwardly against the force of said barrel spring, thus relieving the tension load normally transmitted from the breech bars to the breech block and facilitating extraction of said cotter pin preliminary to removal of said breech block, said lever having a portion 'releasably engageable by said magazine catch device to retain said lever in its retracted position.

References Cited in the tile of this patent UNITED STATES PATENTS 

